Bug 1784130 (CVE-2019-19319)

Summary:	CVE-2019-19319 kernel: out-of-bounds write in ext4_xattr_set_entry in fs/ext4/xattr.c
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, allarkin, bdettelb, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jlelli, john.j5live, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, lgoncalv, linville, masami256, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, qzhao, rt-maint, rvrbovsk, steved, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	An out-of-bounds write flaw was found in the Linux kernel’s Ext4 FileSystem in the way it uses a crafted ext4 image. This flaw allows a local user with physical access to crash the system or potentially escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-04 02:23:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1784131, 1836664, 1836665, 1836666, 1836667, 1836668
Bug Blocks:	1784135

Description Guilherme de Almeida Suckevicz 2019-12-16 18:50:52 UTC

In the Linux kernel 5.0.21, a setxattr operation, after a mount of a crafted ext4 image, can cause a slab-out-of-bounds write access because of an ext4_xattr_set_entry use-after-free in fs/ext4/xattr.c when a large old_size value is used in a memset call.

Reference:
https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19319

Comment 1 Guilherme de Almeida Suckevicz 2019-12-16 18:51:52 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1784131]

Comment 4 Justin M. Forbes 2020-05-13 22:22:00 UTC

That was fixed for Fedora with the 5.2 kernel rebases.

Comment 6 Alex 2020-05-17 17:00:10 UTC

Mitigation:

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Comment 10 Petr Matousek 2020-05-26 12:51:04 UTC

Statement:

This issue is rated as having Moderate impact because of the preconditions needed to trigger the issue (physical access or user interaction to mount the crafted filesystem image).

Comment 11 errata-xmlrpc 2020-11-04 00:50:31 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4431 https://access.redhat.com/errata/RHSA-2020:4431

Comment 12 errata-xmlrpc 2020-11-04 02:22:33 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4609 https://access.redhat.com/errata/RHSA-2020:4609

Comment 13 Product Security DevOps Team 2020-11-04 02:23:47 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2019-19319